KR100333658B1 - Coloring composition for stamping foil - Google Patents

Abstract

The present invention relates to a coloring composition for stamping foils, which can be applied to stamping foils for plastics, to produce a foil having high heat resistance, excellent cutting properties, solvent resistance, and scratch resistance, and which does not change the cutting property over time. This coloring composition is obtained by adding an acid catalyst to a composition consisting of 10-40% by weight of a mixture of nitrocellulose and an acrylic resin as a main material, 20-45% by weight of isoacetate resin and 20-50% by weight of melamine resin as a curing agent. It is preferable that resin is a thermosetting acrylic resin whose OH is 40 or more.

Description

Coloring composition for stamping foil

The present invention relates to a coloring composition for stamping foil, and more particularly, to a coloring composition of a stamping foil for plastics, in which two types of curing agents are mixed to improve heat resistance, scratch resistance, solvent resistance, adhesion, and cutting property. will be.

Stamping foil is a metal that expresses metallic gloss by depositing a metal such as a release layer, a coloring layer expressing color by putting a dye or a pigment to express color, and aluminum on a base film (usually a polyethylene terephthalate film) for coating processing It is a type of laminating a protective adhesive layer that serves to provide the adhesion to the deposition layer and the subject or to protect the deposition layer, the production of the release layer, colored layer, metal on the base film in the same manner as the process of the general hot stamping foil It is made by coating the deposition layer and the protective adhesive layer in order.

Similarly, for plastic stamping foils, this can be applied to fine lines, such as cosmetic cases and the like, or to a large area that covers the front of a plastic cylinder or the like.

In the case of stamping foil applied to a large area, physical properties such as heat resistance, scratch resistance, solvent resistance, adhesive strength, and cutting property are required, and in order to satisfy these characteristics, it is possible only by a curing system such as thermosetting or UV curing. Do.

However, in the case of thermal curing, the degree of heat resistance varies depending on the amount of the curing agent, and if the content of the curing agent increases, the post-curing progresses and the cutting property is excessively deteriorated.

Specifically, when an isocyanate-based curing agent is conventionally used as a colored layer, a polymer having a hydroxyl group and a resin such as acryl that induces cleavage are used. In this case, the resin has excellent heat resistance but is cured after being cured in the residual reactors of the colored layer. Was bad. In addition, in the case of using a melamine-based curing agent, it was used in combination with resins having a hydroxyl group, an amino group, and a karthyl group.In this case, the wear resistance and the solvent resistance are excellent, but post-curing at room temperature does not occur, so the cutting property can be maintained. Although the heat resistance was poor, it was 200 degrees C or less.

The present inventors conducted a study to eliminate the above-mentioned problems in the prior art, and as a result, have found out the composition using two different kinds of curing agents as colored layers and completed the present invention.

That is, an object of the present invention is to provide a coloring composition for stamping foil applied to an industrial plastic that is excellent in physical properties such as heat resistance, solvent resistance, scratch resistance, and does not cause a decrease in cutting property over time.

The coloring composition for stamping foil for achieving the object of the present invention is made by mixing an isocyanate curing agent and a melamine curing agent of a thermosetting resin having a hydroxyl group, a carboxyl group or an amine group that is thermosetting and involved in thermosetting, in an appropriate ratio, According to this, it is possible to obtain a product that satisfies the physical properties required by the colored layer of the stamping foil and has excellent cutting property of the colored layer over time.

Stamping foil to which the coloring composition of the present invention is applied is a conventional coating of a release layer, a coloring layer, a metal deposition layer and a protective adhesive layer on the base film as in the prior art, in the present invention using a polyester film as a base film as a support The release layer is also formed by applying conventional wax, cellulose, acrylic resin, or the like.

However, in the case of the colored layer, a material very different from the conventional one is used. The present inventors have completed a lot of studies to solve the problems of the prior art, and have been completed by finding out the rate at which the post-curing of the isocyanate curing agent starts to occur. That is, the colored layer is 10 to 40% by weight of nitrocellulose or acrylic having a hydroxyl group that isocyanate-based curing agent and melamine-based curing agent react at the same time, 20 to 45% by weight of isocyanate-based and 20 to 45% by weight of melamine-based It is 0.8 ~ 1.3㎛ thick coating layer dried for 10 ~ 30 seconds at the temperature of 150 ~ 180 ℃ by adding and coating acid catalyst to maintain proper acidity in the new composition added ˜50%.

When the content of the isocyanate-based curing agent is more than 45% by weight, the coloring composition to form the above colored layer promotes post-curing and degrades the cutting property, and when the content is less than 20% by weight, the melamine content is increased. Heat resistance falls. In addition, when the weight ratio of hydroxyl group resin, which is the main material, is more than 40%, the cutting property may be lowered.

On the other hand, the acrylic resin using a thermosetting acrylic resin having a hydroxyl value of 40 or more, if the hydroxyl value is less than 40 there is a problem that the curing is not sufficiently made, the heat resistance, solvent resistance and the like.

Next, a metal deposition layer is formed by depositing a metal such as aluminum at a thickness of 300 to 500 kPa on the colored layer, and a protective adhesive layer for plastics commonly used is formed thereon to prepare a stamping foil.

Hereinafter, the Example about the coloring composition for stamping foils which concerns on this invention is described in detail.

Examples 1-3 and Comparative Examples 1-3

Hydroxide resin having a hydroxyl ratio of 40% or more, an isocyanate-based curing agent (TR50 manufactured by Aekyung Chemical Co., Ltd.) and a melamine resin (Cytek's Cymel 325) obtained by mixing nitrocellulose and an acrylic resin having an OH of 50 or more in 1: 2 are shown in Table 1 below. It was mixed in the same composition as this, and 200ppm of paratoluene sulfonic acid was added thereto, and diluted with a solvent such as methyl ethyl ketone, cyclohexanone, and toluene so that the solid content ratio was 20% by weight, and then 10 weights of orange and yellow dyes were added thereto. Part was added and dispersed to make a coloring composition.

Next, a cellulose acetate was coated to a thickness of 0.1 to 0.2 μm according to a conventional method on a 19 μm thick polyester film to form a release layer, and the colored composition prepared above was coated to 1.1 μm thickness for 20 seconds at 160 ° C. It dried and the colored layer was formed.

Then, aluminum was deposited to a thickness of 350 kPa using a vacuum evaporator thereon to form a metal deposition layer, and then an adhesive layer for plastic was applied to form a stamping foil.

Example Comparative example One 2 3 One 2 3 Hydroxyl resin 30 30 25 30 30 45 Melamine resin 35 45 35 - 70 20 Isocyanate Curing Agent 35 25 40 70 - 25

Using stamping foils made in Examples and Comparative Examples, the releasability, cleavage, heat resistance, scratch resistance, solvent resistance and cleavage after time change were evaluated by the following methods, and the results are shown in Table 2.

Dysplasia

As a sensory test, a 1M width of 3M transparent tape was attached to the adhesive surface, rubbed once or twice, and then peeled to evaluate the release surface. If the release surface is clean, it is indicated as C;

Machinability

The release property was evaluated, and the tape side after peeling was observed and evaluated. G on the side of the tape has no jagged afterimage, A on some level, B on severe level.

Heat resistance

The PVC sheet was evaluated by stamping under pressure conditions of 4 kg / cm 2 for 1 second at intervals of 10 ° C. from 150 ° C. to 240 ° C., respectively.

Scratch Resistance

Stamping was performed on the PVC sheet at 150 ° C. for 1 second under a pressure condition of 4 kg / cm 2, and the degree of scratching was observed by rubbing the colored tube 10 times with an appropriate force. Good was marked G, usually A, and severe B.

Solvent resistance

Stamping the PVC sheet was carried out at 150 ℃ for 1 second under the pressure condition of 4kg / ㎠, buried acetone on the colored surface and rubbed with a suitable force to measure the number of times until the dye of the colored layer on the cotton swab.

Cleavage after change over time

After leaving for 10 days at 80 ° C. and 40% RH, progress and evaluation were performed in the same manner as in the cutability evaluation test.

Example Comparative example One 2 3 One 2 3 Dysplasia C C C C C C Machinability G G G A G B Cleavage after change over time G G G B G B Heat resistance (℃) 230 220 220 230 180 170 Scratch Resistance G G G G G A Solvent resistance 60 75 50 70 80 40

Referring to Table 2, it can be seen that when the coloring composition of the present invention is used for stamping foil for plastics, the releasability, scratch resistance, and solvent resistance are similar to or better than those of the existing ones, and particularly, the cutting property and the heat resistance are excellent.

As described in detail above, applying the coloring composition for stamping foils according to the present invention to stamping foils for plastics has a high heat resistance, excellent cutting properties and solvent resistance, and scratch resistance, but does not change the cutting property with time. I can make it.

Claims (3)

(Correction) Coloring for stamping foil formed by adding an acid catalyst to a composition consisting of 10-40 wt% of a mixture of nitrocellulose and an acrylic resin as a main material, 20-45 wt% of an isocyanate-based curing agent and 20-50 wt% of a melamine resin. Composition. The coloring composition for stamping foil according to claim 1, wherein the acrylic resin is a thermosetting acrylic resin having an OH of 40 or more. The coloring composition for stamping foil according to claim 1, wherein the mixing ratio of the nitrocellulose and the acrylic resin is 1: 2 by weight.